Steering mechanism



yJune 27, 1939. R s, SANFORD Er 2,163,892

STEERING MECHANISM Filed Oct. 7, 1956 is ./l' v///////////// INVENTOR.V/cra/P M A2M-5,64 7W BY fors .SAA/fafa I ATTORNEY.

Patented June 27, 1939 UNITED STATES PATENT OFFICE f f' 2,103,392

sirname nacnmsnr any s. saurai-d, New York, N. Y., and victor w.

Kliesrath, South Bend, Ind., mignon to Bendix Products Corporation,South Bend, Ind., a

corporation of Indiana Application October 7, 1936, Serial No. 104,348

2 Claims. (Cl. 66-52) 'Further objects and features of the inventionwill be apparent after a reading of 'the subjoined speciilcation andclaims and after a consideration of the accompanying drawing,` inlwhich:

Figure 1 is a diagrammatic plan view of a fragment of an automobile'withportions shown in section and showing -`details of a preferredembodiment of our invention;

Figure 2 is a fragmentary'view in vertical section showing thearrangement of the control for the hydraulic system; u

Figure 3 is a view in section on an enlarged scale through one of' thecheck valve* arrangements; and i Figure 4 is a view in section and on anenlarged scale taken substantially on the line 4-4 of Figure 1.

Referring in detail to the drawing, there is shown in Figure 2 asteering wheel I0 secured to a steering shaft I2 which extends throughthe dash I4 of an automobile having a floor I6. The steering wheel I ispositioned adjacent to a seat I8 for the operator and the steeringcolumn I2 extends into a gear pump 20. The connection of the steeringcolumn I2 with the gear pump 20 is shown more clearly in Figure 1 whereit may be seen that the pump comprises a pair of gears 22 and 24meshedwith each other and inclosed in a casing 26. The gear 22 issecured upon the steering column I2 and rotation of the column compelsrotation of both of the gears 22 and 24 and thus depending upon thedirection of rotation forces liquid out to one of the conduits 28 or 30to one end or the other of the relatively long hydraulic cylinder 32.

The cylinder 32 is pivotally secured to an arm 33 connected to the axle41 and is provided with a central piston 34 which is connected to a link36, the link being also pivotally connected at 36 to a. iltting 39adjustably threaded on a tierod 40. 'I'he opposite ends of thetie-rod'40 are connected to steering arms 42and 44 respectively whichare in turn connected to the steerable wheels 46 and 48. Thus it may beseenthat ro-` tation of the steering wheel lil operates the pumpv tocause movement of the piston 34 and consequent steering movement of thesteerable wheels 5 46 and 46. Y

Means are provided Vfor maintaining the hydraulic transmission under auniform positive pressure, for :Iilling the system with oil, and forbleeding the system. With the arrangement.l0

shown, the system may be lled with oil such as the `4oils which are'commonly used in hydraulic transmission systems instead of the oilswhich are commonly used in lubricating automobile engines. 1 As may beseen in Figure 1, an engine oil pump. 50 is connected, through a conduit52, a pres-` sure cylinder or reservoir 96,' a conduit 82 and branchconduits 56 and 66, with the conduits 28 and 30. There is incorporatedin the conduit 62 20 a yfitting 60 for filling the system with' oil, andwhich tting will be describedin greater detail hereinafter. AInterposedin the conduit `56 between the conduit 82 and the conduit 30 is a checkvalve 60, and interposed in the conduit 58 bel 25 tween the conduit 62and the conduit 26'is a check valve 62. These check valves are identicaland are-shown more clearly in Figure 3. As may be seen, thevalves 60 and62 are simple one-way check valves, each comprising a casing 64,A ab"al1 30 66 within the casing resiliently urged to its seat by a spring66. The pump 5I! draws oil from any suitable source, as, for example,from the sump of the engine through a conduit 10, and delivers this oilunder pressure to the pressure cylinder 96 vla conduit 52 and a conduit54. 'I'he conduit 52 is also connected to a conduit 53, which leads tothe part of the engine which it is desired to lubricate by oil underpressure.

Means are provided to bleed the hydraulic system for the elimination ofair or other gases which might from time to time become included in theoil used for the hydraulic steering. For this purpose there are providedbleed openings 'I4 and 16 in the hydraulic cylinder 32 at the highest 45Describing now in greater detail the tting 6U,

the same is interposed in the conduit 82 and is provided with a bore 64connecting the two sections of the conduit. Intersecting the bore 84 isa bore 66, the outer end o! which is provided with a plug 88, which isremoved when the nozzle of a pressure pump is attached for .supplyingadditional liquid into the system. Interposed in the bore 86 is a plugvalve 90 provided with a handle 92 by which the valve may be rotatedfrom its normal cut-off position, as shown, to a position to align abore 94 with the bore 85, so that liquid may be forced into the system.Provided the bleed openings 14 and 16 are open, this liquid will passthrough the check valves and 62 and illl the conduits 28 and 30 and thecylinder 32, carrying out through the bleed openings any air or othergas which may be included. Also, as may be clearly seen, the pump 20will also be illled with liquid. Liquid will also be forced into thelower end of a pressure cylinder 96 or reservoir to force upward thereina piston 98 compressing the spring 85 until that cylinder is filled withliquid.

The upper end of the reservoir 96 is connected by the conduit 54 withthe conduit 53 through which lubricating oil for the bearings of theengine is supplied by the lubricating pump 50. Adjacent the lower partof the reservoir 86 it is provided with a by-pass opening 91 as a safetyprecaution. Normally this by-pass will not be used and the liquid in thehydraulic transmission system will be kept under pressure by the springacting on the piston 98 and thus maintaining a positive pressure on theliquid in the conduit 82 and supplying additional liquid to the conduits28 and 30, should those conduits, the pump 20 or the cylinder 32 loseany liquid by leakage. In the event, however, that, due to a delay insupplying additional liquid when needed to the fitting 88, the piston 98approaches the lower end of the reservoir 86, then additional liquidwill be forced into the hydraulic transmission system from thelubricating system. This is automatically taken care of, inasmuch asafter the piston 88 has passed the upper end of the by-pass 91lubricating oil may iiow through the by-pass around the piston to thelower end of the cylinder.

The operation will now be described. Should the operator desire to steerthe vehicle in either direction, he will rotate the steering wheel I0 inthe customary manner so as to rotate the steering column I2. Thus, ifthe steering column I2 is rotated in a clockwise direction as seen inFigure 1, it rotates the gears 22 and 24 so as to draw iluid from theconduit 28 and force the iluid into the conduit 30, thus forcing fluidinto the right-hand end of the cylinder 32 and withdrawing iluid fromthe left-hand thereof. This moves the piston 34 to the left as shown inFigure 1, and moving the tie-rod 40 in a similar direction rotates thesteering arms 42 and 44 to rotate both of the steerable wheels 46 and 48also in a clockwise direction to turn the vehicle to the right as seenin Figure 1. 'Ihe pressure fluid used for the transmission of power ismaintained in the system and under a predetermined pressure by thespring 85 supplemented by the pressure derived from the pump 50.Bleeding may be accomplished by the lubricatingv pump 50, when desired,bythe removal of the bleeder screws associated with the bleeder openings14 and 16.

While one illustrative embodiment has been described, it is not ourintention to limit the scope o! the invention to that particularembodiment, or otherwise than by the terms of the appended claims.'

We claim:

1. Means for maintaining pressurein a hydraulic system comprising anengine lubricating pump, a conduit connecting said engine lubricatingpump with the hydraulic system, a check valve interposed in saidconduit, and a reservoir also interposed in said connection and providedwith a piston normally separating the lubricating oil from the oil ofthe hydraulic system.

2. Means for maintaining pressure in a hydraulic system comprising twoseparate means providing iluid under pressure, fluid transmittingconnections interconnecting said two separate means or sources ofpressure with the hydraulic system, means interposed in said connectionsand constituting an element of said connections, said latter meansincluding a reservoir, and valvular means therein automaticallyoperable, in the event o! the inadequacy of one of said sources ofpressure to maintain the pressure of the system, to bring into play theother of said sources of pressure.

ROY S. SANFORD. VICTOR W. KLIESRATH.

